This invention relates generally to pumps and more particularly to variable flow rate pumps for hydraulic systems.
Aircraft gas turbine engines often incorporate various high pressure hydraulic actuators to operate components such as variable geometry exhaust nozzles, vectoring exhaust nozzles, bypass doors, variable stator vanes, and the like.
Depending on which actuators are being used, the flow requirements vary greatly, and it is desirable to match pumping capacity to the demand. Variable displacement high-pressure piston pumps are therefore commonly used in engine and aircraft hydraulic systems. However, prior art variable displacement piston pumps can be complex, heavy, costly and can lack desired reliability.